a) Field of the Invention
The invention is directed to a multiple-axis inclinometer for measuring inclinations and changes in inclination, especially for precision measurements with geodetic devices.
b) Description of the Related Art
Devices with a cuvette or cell with a liquid forming a horizon are used for precise measurements of inclination. A projected light bundle is reflected at this liquid horizon.
Conventional biaxial inclinometers have a prism with a cell and separate optics which serve to image a pattern of cross-lines on a CCD line via a liquid horizon on the transmitter side or via a surface sensor on the receiver side. An imaging system and a measurement system which are arranged perpendicular to one another are provided for each direction of inclination. In this respect, it is difficult to accommodate the four optical systems of the crossed imaging systems in a very compact space.
These difficulties are overcome by a biaxial inclinometer according to DE 198 19 6510 which is constructed in a very simple manner. A thick plano-convex lens at the base of a liquid cell takes over the function of illumination optics as well as imaging optics for cross-line patterns which are imaged on a CCD line. Corresponding measurement values are determined for the inclinations by displacing the images of the cross-line patterns on the CCD lines.
DE 41 10 858 describes a biaxial inclinometer which has an imaging system and a cross-line pattern which has cross-lines arranged at right angles to one another and is illuminated by a light source in the transmitter plane. This cross-line figure has at least one angle whose imaged side intersects a CCD line at two points. Measurement values for determining the transverse and longitudinal inclination of the device can be derived from the change in distance or from the simultaneous common displacement of these two points occurring when the device is inclined and corresponding inclination values are determined from these measurement values. This inclinometer does not need intersecting illumination and imaging systems for the cross-line pattern. However, it is disadvantageous that only inclinations in a small angular range can be measured. Also, the arrangement of illumination optics and imaging optics has a negative effect on the size of the inclinometer in that there can be no reduction below certain boundary magnitudes.